Detergent-hydrotrope composition



United States Patent O US. Cl. 252137 9 Claims ABSTRACT OF THE DISCLOSURE A slurry, light-duty liquid or heavy-duty liquid detergent composition containing a water-soluble alkylethoxy sulfate as a hydrotrope.

CROSS REFERENCES TO RELATED APPLICATIONS This is a continuation-in-part of applicants copending application of the same title, filed July 22, 1964, Ser. No. 384,539, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to fluid detergent compositions of the alkylbenzene sulfonate type, and particularly to slurry compositions and liquid compositions.

Description of the prior art In the manufacture of alkylbenzene sulfonate detergents, it is conventional to form a so-called slurry of detergent and water, each being present in a major proportion. This slurry has a paste or cold cream consistency. The viscosity of the slurry is very high, thereby imposing line size limitations as Well as large pumping requirements on the use of these slurries. The simple expedient of adding more water is unsatisfactory because the active component content is thereby decreased and more inert material must be transported. It is known that certain compounds will increase the solubility of the sulfonate in Water and markedly decrease the viscosity of a given slurry; these compounds are called hydrotropes by the art.

Liquid detergents, both light duty and heavy duty, have problems with clarity because the washing effec* tiveness needs push the detergent content towards the saturation point at normal temperatures. Hydrotropes are used with these compositions to increase the solubility of the alkylbenzene sulfonate detergents and thereby lower the cloud point of the composition.

An object of the invention is a slurry detergent composition which has a lower viscosity at a given alkylbenzene sulfonate and water content than conventional compositions; or has a higher alkylbenzene sulfonate content at a given viscosity than conventional compositions.

A particular object of the invention is an alkylbenzene sulfonate liquid, light-duty detergent having a low cloud point.

A further object is an alkylbenzene sulfonate liquid, heavy-duty detergent having a low cloud point.

Other objects of the invention will become apparent in the course of the detailed description thereof.

BRIEF SUMMARY OF THE INVENTION In its broadest aspect the invention encompasses a fluid detergent composition consisting essentially of (a) water-soluble alkylbenzene sulfonate having about 816 alkyl carbon atoms; (b) alkylethoxy sulfate, having 4-10 alkyl carbon atoms, and about 15-55% of ethylene oxide units, in an amount at least suflicient to increase the water solubility of said sulfonate; and (0) liquid water, in a major proportion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In one embodiment the invention encompasses a slurry detergent composition consisting essentially of (a) Water soluble alkylbenzene sulfonate having about 8-16 alkyl carbon atoms in an amount of about 30 to 50%; (b) 91- kylethoxy sulfate, having 4-10 alkyl carbon atoms, and about 15-55% of ethylene oxide units, in an amount of about 2-10% based on said composition; and (c) the remainder liquid water in an amount suflicient to afford a pasty slurry composition.

In another embodiment the invention encompasses a liquid, light-duty detergent composition including (a) alkylbenzene sulfonate having about 8-16 alkyl carbon atoms, about 18-32%; (h) alkylethoxy sulfate, having 4-10 alkyl carbon atoms and about 15-55% of ethylene oxide units, in an amount of about 515%, and (c) at least one member of the class consisting of: 1) foam stabilizer, (2.) ethoxy nonionic detergent, and (3) alkylethoxy sulfate detergent having at least about 12 alkyl carbon atoms, wherein said stabilizer, if present, is present in an amount of about 2-10% and said detergent, if present, is present in a total of about 10-25%; and (d) liquid water, as essentially the remainder.

In still another embodiment the invention encompasses a liquid, heavy-duty detergent composition including (a) alkylbenzene sulfonate having about 846' alkyl carbon atoms, about 13 to 25%; (b) a potassium polyphosphate compound, about 10 to 30%; (c) alkylethoxy sulfate, having 4-10 alkyl carbon atoms and about 15-55 of ethylene oxide units, in an amount of about 545%; and (d) similarly to the light-duty formulation above, a foam stabilizer, an ethoxy nonionic detergent or an alkylethoxy sulfate detergent. In general, the molecular weight of the alkylbenzene sulfonate constituent used in heavy-duty formulations may be slightly higher than that used in light-duty formulations.

It has been discovered that linear alkylbenzene sulfonate detergent compositions are surprisingly more responsive to the alkylethoxy sulfate hydrotrope than the highly branched alkylbenzene sulfonates, such as propylene tetramer benzene sulfonate.

The invention is directed to fluid detergents composition which includes the very viscous paste or cold creamy types commonly called detergent slurry and the low viscosity compositions commonly called liquid light-duty and liquid heavy-duty detergentsthese are true solutions. In all of these fluid detergents, liquid water is present in a major proportion; in the light-duty liquid detergent compositions, the water'normally forms more than 50% of the composition; whereas in the heavy-duty liquid compositions, the water content is less than but in the neighborhood of 50%. The amount of water present in slurry compositions is dependent on the viscosity desired and the hydrotrope content, but is usually on the order of the sulfonate content. Always the water and the sulfonate detergent are the major components of the fluid detergents of the invention.

The detergent compositions of the invention may be classified as a water-soluble alkylbenzene sulfonate type. In these sulfonates the alkyl carbon atoms total about 8-16, commonly 12-14. These include the highly branched alkylbenzene sulfonates (ABS) and the linear alkylbenzene sulfonates (LABS)-the so-called biodegradable type. Illustrative of the ABS type are those derived from benzene and butylene trimer and propylene 3 tetramer. Illustrative of the linear ABS type are those derived from benzene and monochloro-straight chain hydrocarbons, such a monochlorododecane. The linear alkylbenzene sulfonates are preferred.

.The amount of defined sulfonate present will be dependent on the fluid composition wanted. In the case of light-duty liquid detergents, about 18-32% will generally be defined sulfonate. In the case of heavy-duty liquid detergents, about 13-25% Will generally be defined sulfonate. (Herein all percentages are weight percent and are based on the total detergent composition.)

The detergent composition of the invention includes a water-soluble alkylethoxy sulfate as a hydrotrope. This alkylethoxy sulfate may be depicted: R(OC H 050 M where R is an alkyl group having 4-10 carbon atoms with from 4-8 carbon atoms being preferred, it is equal to at least 1 and M may be any ion or radical conventionally known in the detergent art in connection with water-soluble detergent sulfates. R may be branched or straight-chain, although a straight chain (n-alkyl) is preferred.

The alkylethoxy sulfate includes at least about 1 ethylene oxide unit. When an alkanol and ethylene oxide are reacted, a spectrum of alkylethoxy compounds is obtained, along With unreacted alkanol. It is customary to average the ethylene oxide units added over the product mixture and it is common to have amounts Which are not integers. In some cases, the alkylethoxy sulfate used in the composition of the invention may have an ethylene oxide unit content of somewhat less than 1 unit per molecule.

For the purposes of this specification the ethylene oxide content of the hydrotrope here is defined according to another convention of the art, namely, weight percent of ethylene oxide units present based on the ether alcohol intermediate.

The alkylethoxy sulfate hydrotrope here contains between about 15 and 55% of ethylene oxide units..

The alkylethoxy sulfate hydrotrope may include only one alkyl species or it may include more than one species as where the ether alcohol is prepared from a mixture of alkanols, for example, ALFOL 610 alcohols (trade name of Continental Oil Company) which contains n-alkanols of 6 carbon atoms 21% by weight, 8 carbon atoms 36% and 10 carbon atoms 43%. With such mixtures it is preferred that at least half of the species be of the 6 or 8 carbon atom variety.

Sufficient alkylethoxy sulfate hydrotrope is present in the fluid detergent composition to increase the water solubility of the defined sulfonate detergent. Commonly, this is observed as a decrease in viscosity of a slurry detergent or lowering of the cloud point of a liquid detergent. The minimum amount is determined not only by the particular detergent present but also by the presence of other hydrotropes. In general, an economic limitation exists whereas no worthwhile improvement is obtained with further addition of this hydrotrope.

In the case of slurry detergent compositions, the usage of the defined alkylethoxy sulfate hydrotrope is between about 2 and 10% and more usually about -10%. In the case of liquid, light or heavy duty detergent compositions, the usage is between about 5 and 15% and more usually about -15%.

Commonly, the alkylethoxy sulfates are available as aqueous solutions. It is to be understood the aforesaid usages are based on 100% active material.

Liquid, light-duty detergent compositions include, in addition to the alkylbenzene sulfonate detergent and hydrotrope, either a foam stabilizer or another detergent or both. Any of the foam stabilizers now used may be used with the defined hydrotrope. Among the materials which may be employed are amine oxides; members of the fatty alcohol series, such as lauryl alcohol; fatty diethanolamides, such as coco-fatty diethanolamide; fatty alkylamides; free fatty acids and their esters with lower monohydric alcohols or glycols; saponins; higher aliphatic 1,2-diols, such as hexadecane-1,2-diol; imides of dicarboxy acids, such as 4-Octadecene-1,2-dicarboxylic acid imide; and esters of aryl phosphoric acid, such as the sodium salt of the methylester of p-tert-octylbenzenephosphoric acid. The other detergent may be an ethoxy nonionic detergent or an alkylethoxy sulfate detergent having at least about 12 alkyl carbon atoms. The thoxy nonionic detergent preferably has 10-18 alkyl carbon atoms and about 50-65% ethylene oxide unit content. Operable materials include the condensation product of ethylene oxide with a fatty acid-containing material such as tall oil, alcohols, esters, aldehydes, amids, amines, a phenolic compound having lateral alkyl side chains, and the like.

Liquid heavy-duty detergent compositions include, in addition to the above-named ingredients of the light-duty formulations, a potassium polyphosphate compound. The complex or molecularly dehydrated polyphosphate salts are generally used in the form of the normal or completely neutralized salts, e.g., tetrapotassium pyrophosphate and pentapotassium tripolyphosphate. Partially neutralized salts, such as potassium acid tripolyphosphate, may also be used. Mixtures of these materials may be used, but it is preferred that such mixtures include an effective amount of tetrapotassiurn pyrophosphate.

A particular embodiment of a slurry detergent composition, of the invention consists essentially of (a) alkylbenzene sulfonate having about 12 alkyl carbon atoms derived from propylene tetramer, about 40%; (b) sodium sulfate, about 5%; (c) hexylethoxy sulfate having about 2 ethylene oxide units, about 5%; and (d) liquid water, about 50%. The sodium sulfate in gredient enhances detergency power but is not an essential ingredient of the formulation.

When a foam stabilizer is part of the light or heavy duty composition, it is present in an amount of about 210%. When the other defined detergent is part of the light or heavy duty composition, it is present in an amount of about 10-25%; should more than one of the other defined detergents be present, the total content is about 10-25%.

Various other ingredients may be added to the detergent composition as desired, including compatible perfumes, coloring materials, corrosion or antitarnishing inhibitors, e.g., silicates, germicides, bleaching agents, optical bleaches or fluorescent brighteners, and the like. It is desirable to add a minor amount, such as A1-5% by weight, of a soil anti-redeposition agent, e.g., cellulose ethers. Suitable examples are methyl-, ethyl-, and hydroxyethylcellulose, alkali metal carboxymethylcellulose. In some cases, a lower alcohol may be present.

An especially suitable liquid, light-duty detergent composition includes (a) linear alkylbenzene sulfonate having about 12 'alkyl carbon atoms, about 25%; (b) lauric diethanolamide foam stabilizers, about 5%; (c) hexylethoxy sulfate having about 2 ethylene oxide units, about 10%; and (d) liquid water essentially the remainder.

The anionic detergents and sulfates which are or may be present in the detergent compositions of the invention are used in the form of their water-soluble salts, such as the alkali metal, alkaline earth metal, ammonium, amine, and alkylolamine salts. While the sodium, potassium, ammonium, and alkylolamine (e.g., mono-, di-, and triethanolamine) salts are preferred ordinarily, other salts such as the lithium, calcium, and magnesium salts may be used if desired. For general use, it is preferred to use the sodium and potassium salts.

5 ILLUSTRATIONS I Here a slurry detergent in an as produced condition had an unmanageable high viscosity. The as produced slurry analyzed: propylene tetramer-benezene 5 HI sulfonate (sodium) 46%- sodium sulfate 5% unreacted Liquid light duty detergents were formulated which all; lbenzene, about 17 and water 487 y differed only in the detergent present. Each formulation Ia included 25% of detergent; 5% of lauric diethanolamide A typical commercial formulation was prepared by foam stablhzer; f the remamder Wateradding 5 parts of xylene sulfonate hydrotrope to 100 For comparatfve 17111130565 east} of the QY formula parts by Weight of the as produced Slurry. The Xylene trons was made nto a corresponding composition by addsulfonate was in the form of an aqueous solution containmg of acme hydrotrope- These lncludefi the ing about 40% of the active materiaL ventional hydrotropes: ethanol, urea and sod1um xylene sulfonate. In another, sod1um hexyl sulfate was added- 1b this was made by sulfating ALFOL 6 alcohol. In A comparative formulation was prepared by adding 12 another, Sodium h xyl xy Sulfate was parts of liquid Water to 100 parts of the as produced ildded- T Cloud was detefmlned for each Slurry composition. Formulation IIIa contained propylene 1c tetramerbenzene sulfonate (sodium). Formulation IIIb c Another formulation was Prepared by addmg 10 Parts sillillilioi liii coiliiiii iiiiifi nfiiiifiilialiii fii :1 1d 2 i t s g f li iiit i v itfiir ilf5$ffigg by sulfating Arrow 1218 alcohol which is a mixture of P q Y n-alkanols having 12, 14, 16, and 18 carbon atoms. The from ALFOL 6 alcohol containing essentlally only 6 results are Set out in Table In carbon atoms to which was added 2 ethylene oxide units (46.5% ethylene oxide) and then converted to sod1um TABLE III hexylethoxy sulfate (46.5% EtO). D

The viscosity of formulations la, lb, and 16 Was f- Hydrotrope IIIb 1110 $221.1 The formulations and viscosmes are pr n In (Detergent) (ABS) (LABS) (1H8 As) None 142 170 12 TABLE I lfiythanol 73 I63. Formulation Ia 1b 1c fiylerlre Lsfilflfgnata 28 26 ex s a e 46 27 6 svlgggnaagd griducei 9% Hexlethoxy sulfate 38 22 15( ggiggene sulltortiatefiiict iv e 5 B viscisit i e h i b isesil- 0,'000"",'606' 34,000 The results in Table III show the astounding fact that the alkyethoxy sulfate is detrimental to the alkyl sulfate 11 40 detergent cloud point. All the other materials showed Tests similar to the above are made on various slurries g gig 3 322 53 f 1 igg zggg' t 1 containing 46% by Weight of various linear alkylbenzene effective fig either ethanol g 2 a t 655 sulfonate detergents and remainder water. To 100 parts or y ens su ona e still it is an excellent hydrotrope. by welght of thls Slurry are added 10 Parts 50% Sur risin 1 in com osition IIIb the hex 1 th 1 aqueous solutions of various alkylethoxy sulfate hydrofate a 2 effeclzive h drotr e i Kg tropes and 2 parts water. The results of viscosity measure- 1 P 3 a merits on thfise slurries are presented in Table H were substantial y less effective, xylene sulfonate was es sentially the same; hexyl sulfate Was significantly better TABLE 11 than urea and ethanol and equal to xylene sulfonate. The Linear Alkylbenzene Viscosity difference between 111a and IIIb is even more striking Example Sulfonate Alkyletmxy Sulfate (ps3 when the 28 F. higher cloud point of the no-hydrotrope Ila sodilum otctylbenzene None* 73,000 formulation iS taken into account. IIb Sodium hexylethoxy 20, 000

sulfate, 46.5% EtO. IV 110 Sodium hexadecylben- None 85,000

zene sulfonate. IId do Sodium hexylethoxy 35,000 Tests similar to the above are made on other linear sodi dodec mew gggffffi 'i? 81 000 alkylzenzene sulfonate detergent-containing light duty IIe um y r zene sulfonate. 1 3 00 liquids. Each formulation contams 25% by weight deter- Hf if8 gent, 5% foam stabilizer or 10% other detergent, and Hg -.d0 Sodi um buty e t g y 33,000 remainder water. To parts by weight of each formula- IIh do sohiiiiii ct ithoxy 34,000 tion a a d 10 parts of active alkylethoxy sulfate 1 hydrotrope. The results of cloud point determinations Contained 12 parts water. are set out 1n Table IV.

TABLE IV 0111 Example Linear Alkylbenzene Sulfonate Other Additive Alkylethoxy Sulfate F.)

We Sodialm octylbenzene sulfonate Laulic diethanolamide lgloi ewhfl"n21 l I.f E 1 5 7 EE6 1% Vb. 0 0 mm ex e oxysu ae, lVc Sodiu n hexadecylbenzene sulfonate do goineflnfinl rifi nfiYnagiyounu 13g Vd 0... o rum exye oxysu ac, IlVe Sodiu in dodecylbenzene sulfonate "do... Sodium hutylethoxy sulfate, 15% lEtO 25 IVf. d0 d0 Sod um octylethoxy sulfate, 55% Et0 21 IVg Ethogy 11(111101111 d5(gt7er%atn(t):)(12 alkyl Sodlum hexylethoxy sulfate, 15% EtO. 26

a II a ms IVh c r 0 0 a 20 .do Ltiltrglethoxy sulfate detergent (32% d0 These results show that the various alkylethoxy sulfates tested all acted as effective hydrotropes for the various slurries.

7 All alkylethoxy sulfates tested are effective hydrotropes for the light duty liquid formulations tested.

Additional tests are made similar to the above on heavy duty liquid formulations containing 10% by weight detergent, 20% tetrapotassium pyrophosphate and remainder water. To 100 parts by Weight of each formulation are added 7 /2 parts of active alkylethoxy sulfate hydrotrope. The results of cloud point determinations are set out in Table V.

TABLE V Cloud Linear Alkylbenzene Alkylethoxy Point Example Sulfonate Sulfate F.)

Va Dodecylbenzene sulfonate None 205 Vb ..do Sodium butylethoxy 50 sulfate, 15% EtO. Vc do Sodium hexylethoxy 45 sulfate, 46.5% EtO. Vd do Sodium octylethoxy 53 sulfate, 55% EtO.

(c) the remainder liquid water in an amount sufficient I to afford a pasty slurry composition.

2. The composition of claim 1 wherein said sulfonate is a linear alkylbenzene sulfonate.

3. A slurry detergent composition consisting of:

(a) alkylbenzene sulfonate having about 12 alkyl carbon atoms derived from propylene tetramer, about 40% by weight;

(b) sodium sulfate, about 5% by weight;

() hexylethoxy sulfate having about 2 ethylene oxide units, about by weight; and

(d) liquid water, about 50% by weight.

4. A liquid, light-duty detergent composition consisting of:

(a) alkylbenzene sulfonate having about 8-16 alkyl carbon atoms, about 18-32% by weight;

(b) alkylethoxy sulfate, having 4-8 alkyl carbon atoms and about 15-55% by weight of ethylene oxide units, 5

in an amount of about 5-15 by weight; (c) at least one member of the class consisting of:

(1) ethoxy nonionic detergent, and

(2) alkylethoxy sulfate detergent having at least about 12 alkyl carbon atoms, wherein said detergent is present in a total of about 1025% by weight; and

(d) liquid water, the remainder.

5. The liquid detergent composition of claim 4 wherein said sulfonate is linear alkylbenzene sulfonate.

6. The liquid detergent composition of claim 4 wherein said nonionic detergent is alkanol ethoxy ether having 10-18 alkanol carbon atoms and about 50-65% by weight ethylene oxide units.

7. A liquid, light-duty detergent composition consisting (a) linear alkylbenzene sulfonate having about 12 alkyl carbon atoms, about 25% by weight;

(b) lauric diethanolamide foam stabilizer, about 5% by weight;

(c) hexylethoxy sulfate having about 2 ethylene oxide units, about 10% by Weight; and

(d) liquid water, the remainder.

8. A liquid, heavy-duty detergent composition consisting of (a) alkylbenzene sulfonate having about 8-16 alkyl carbon atoms, about 13-25% by weight;

(b) alkylethoxy sulfate, having 4-8 alkyl carbon atoms and about 15-55 by weight of ethylene oxide units, in an amount of about 5-15 by weight;

(c) a potassium polyphosphate compound, in an amount of about 1030% by weight;

(d) at least one member of the class consisting of:

(1) ethoxy nonionic detergent, and

(2) alkylethoxy sulfate detergent having at least about 12 alkyl carbon atoms, wherein said detergent is present in a total of about 10-25% by weight; and

(e) liquid water, the remainder.

9. The liquid detergent composition of claim 7 wherein said sulfonate is linear alkylbenzene sulfonate.

References Cited UNITED STATES PATENTS 7/1964 Noad 252161 1/1966 Marion 252-137 OTHER REFERENCES Perlman: Detergent Biodegradability, Chemical Specialties, 1963, pp. 68-70, 206, 207.

O LEON D. ROSDOL, Primary Examiner M. HALPERN, Assistant Examiner US. Cl. X.R.

Soap and iggg UNITED STATES PATENT OFFICE J CERTIFICATE OF CORRECTION Patent No. 3501409 Dated March 7, 970

Invgntpr(5) Ted P. Matson, Henry T. Watanabe and Dean R. Weimer It is certified that error appear; in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

I k "I The name of Dean R. Weimer was omitted as a co-inventor in column 1, line 3.

,SIGNED AND swan Anon:

mm M. mum. Ir. mm x. .m, Awning Officer cmmaamm Paton 

